I work in software and also run some pretty active open source projects, so I worry about this happening to me. I've felt somewhat burned out, or felt close to a more serious burn out, on a few occasions. What has helped me is to remind myself that ultimately I don't owe the open source community anything. I do it because I enjoy it, and want to create things for people to use. But if it's creating stress, I take some time off, spend a few weeks playing video games or spending more time with my partner, and that in turn reminds me that the world does not end when I stop programming for a few days. In other words, I haven't stopped, I've just slowed down, and participated in free time open source development with better moderation.